Softstarter operates low-voltage motors to 1,800 hp.

Press Release Summary:

UL-listed Series PST is available for operating voltages from 208-690 Vac and full load line currents of 30-1050 A. When used on wye-delta wound motors, it is capable of inside-the-delta operation and uses automatic sequencing algorithm to adjust SCR firing without manual input. Offered with 2-line, graphical LCD, unit allows for storage of 3 motor parameter sets and machine-to-machine networking. Softstarter provides smooth acceleration of driven load and includes soft-stop feature.

Original Press Release:

ABB Releases New Generation of Softstarter; PST softstarters available for low Voltage motors up to 1800HP

ABB, a leader in power and automation, has developed a new generation of softstarters. The PST series of softstarters are available for operating voltages from 208 to 690VAC and full load line currents of 30 to 1050 Amperes. When used on wye-delta wound motors, PST softstarters are capable of "inside the delta" operation and are UL listed for starting motors up to 1800HP.

"Inside the delta" refers to the capability to be inserted electrically into the motor windings for a six or twelve lead wye-delta motor. When used "inside the delta" the PST softstarters only conducts the phase currents, which are 52% lower than the line currents. When connected "inside the delta", the PST softstarters feature an automatic sequencing algorithm that correctly adjusts SCR firing with no manual input required.

Each PST softstarter includes a large 2-line graphical liquid crystal display (LCD) that provides plaintext communication in any 1 of 12 user selectable languages. By communicating in the user's native language, PST softstarters allow for quick setup of advanced motor protection features. Some of the features included are: adjustable electronic overload, over/undercurrent protection, phase imbalance, phase reversal, and locked rotor. These customizable motor protection features help reduce nuisance tripping, while still insuring a high level of motor protection. In addition, PST softstarters allow for storage of three different motor parameter sets, making the PST ideal for sequential starting of multiple motors or multi-speed motors.

In addition, the PST softstarters offer machine to machine networking. By using ABB FieldbusPlug(TM)technology, the PST softstarters can utilize many of the leading communications protocols. Included in this range are DeviceNet, ProfiBus DP, and TCP/IP over Ethernet.

Primary applications for the PST Softstarter include: pumps, fans, blowers, centrifuges, mixers, and conveyors.

Unlike other starting methods, PST softstarters provide smooth acceleration of the driven load. This prolongs the life of mechanical components such as coupling and belts and gearboxes. By utilizing closed loop current control PST softstarters help minimize the impact of motor starting on the electrical network.

In addition, all PST Softstarters include a soft stop feature. When engaged the PST soft stop feature results in a slower, gentler stopping of driven load. This eliminates "hammering" in pumping systems and prolongs the life of gearboxes and drive belts when operating compressors, mixers, and conveyors.

PSS Softstarters are UL Listed, CSA Certified, and CE approved. They are available through distributors throughout the world.

ABB ( is a leader in power and automation technologies that enable utility and industry customers to improve performance while lowering environmental impact. The ABB Group of companies operates in around 100 countries and employs about 135,000 people. The company's U.S. operations employ about 11,000 in manufacturing and other facilities in 40 states.

For more information, visit our web site at or call ABB at (888) 385-1221.

For more information please contact:

Low Voltage Products & Systems
ABB is an ISO 9001 company.
Technical Assistance (888) 385-1221
Visit the online catalog at
Send leads to: 1206 Hatton Rd., Wichita Falls, TX 76302

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